Cannot fetch submodule on ARM: "fatal: reference is not a tree"

Hi

Fetching submodule produces a error on ARM builds: https://travis-ci.com/pavelkryukov/putty-aes-ni/jobs/250247395
Meanwhile, same environment works on x86: https://travis-ci.com/pavelkryukov/putty-aes-ni/jobs/250247393

Could anyone please take a look? Maybe there is an old Git version…

Thanks,
Pavel

fatal: reference is not a tree: means that there’s no such commit.

Indeed, https://github.com/pavelkryukov/putty-ci/commit/25b1f33f6d38752c967f0878a16dee86655af70e gives a 404.

The submodule must have been force-pushed between the time the jobs were run.
Build log shows that the 3rd job started about the same time as the first two but multi-cpu jobs typically run noticeably slower than amd64 ones.